Flame arrestor

ABSTRACT

Disclosed herein is a flame arrestor for the air intake of an internal combustion engine having improved resistance to the ingress of moisture into the air intake and including a plurality of arcuate fin elements which have a generally inverted V-shaped cross section and which are stacked in vertically spaced relationship to form an annular assembly, a base having a barrel section adapted to be received by the air intake and an annular ledge extending radially from the barrel section for supporting the fin element assembly, and a cover overlying the fin element assembly and the base. The cover includes an outer portion which extends radially beyond the outer edges of the fin elements and the base to prevent impingement of water draining from the cover onto the fin elements. Moisture collecting on the base ledge is prevented from draining into the air intake by an integral annular raised portion which is located adjacent to the inside edges of the bottommost fin elements to act as a barrier or dam. One or more openings are provided in the outer perimeter of the ledge to afford overboard drainage of moisture from the ledge and the fin elements.

United States Patent 1191 Norton 1 51 Sept. 9, 1975 1 1 FLAME ARRESTOR [75] lnvcntor: Raymond F. Norton Waukegan, Ill.

[73) Assignee: Outboard Marine Corporation.

Waukegan, Ill.

[22] Filed: June 8, 1973 {2]} Appl. No: 368,462

52 us. c1. 48/192; 55/2714; 55/3115; 55/n1c. 2x; 6U/39.l 1; 122/142; 123/1911 D; 220/88 A: 26l/DIG1 6; 431/346 1 1 1m. c1.'- .1171) 3/00 [58I Field 61 Search 421/192; 123/198 E, 198 D, 123/142; 220/88 A; 261/1, DIG. 6; 43l/346; 222/189; 55/385 2721, DIG. 2x. DIG. 20;

60/3911; 126/85 R. s5 A Prmmry E.\um1'nerS. Leon Bashore Assistant Era/ninerPeter F. Kratz Armrney. Agent, or FirmMichael, Best & Friedrich [57] ABSTRACT Disclosed herein is a flame arrestor for the air intake of an internal combustion engine having improved resistance to the ingress of moisture into the air intake and including a plurality of arcuate fin elements which have a generally inverted V-shaped cross section and which are stacked in vertically spaced relationship to form an annular assembly, a base having a barrel section adapted to be received by the air intake and an annular ledge extending radially from the barrel section for supporting the fin element assembly, and a cover overlying the tin element assembly and the base The cover includes an outer portion which extends radially beyond the outer edges of the tin elements and the base to prevent impingement of water draining from the cover onto the tin elements. Moisture collecting 0n the base ledge is prevented from draining into the air intake by an integral annular raised por tion which is located adjacent to the inside edges of the bottommost tin elements to act as a barrier or dam. One or more openings are provided in the outer perimeter of the ledge to afford overboard drainage of moisture from the ledge and the tin elements.

7 Claims, 6 Drawing Figures FLAME ARRESTOR BACKGROUND OF THE INVENTION This invention relates to flame arrestors for an air intake of an internal combustion engine.

As a safety precaution, various internal combustion engines, such as marine propulsion engines, are commonly provided with fire arrestors which are mounted over the air intake of the carburetor to prevent the propagation of back firing flames from the carburetor. Although providing adequate protection against the propagation of back firing flames, prior art flame arrestors often did not provide adequate protection against the ingress of water into the carburetor air intake, which of course can adversely affect the engine performance.

Filed herewith with the Patent Office is a copy of a drawing illustrating two different prior art flame arrestors.

SUMMARY OF THE INVENTION The invention provides a flame arrestor for an internal combustion engine including a plurality of verti' cally spaced fin elements which are assembled to form an annular stacked array, a base having a barrel section adapted to be received by the air intake and an annular ledge which extends radially outwardly from the barrel section and on which the fin element assembly is supported, and a generally horizontal cover overlying the fin element assembly. The fin elements are provided with an outer portion which inclines downwardly to prevent moisture from collecting thereon. Means are provided for preventing the impingement of moisture draining from the cover onto the fin elements. More specifically, the cover is provided with an outer portion which extends radially outwardly beyond, i.e., overhangs, the outer perimeter of the fin elements and the ledge of the base.

Means are also provided for preventing moisture which may collects on the ledge from draining into the engine air intake. More specifically, such means includes a continuous annular raised portion which is integral with the base ledge and is located adjacent to the inner edges of the bottommost fir. elements to act as a barrier or dam.

Also, means are provided for affording the overboard drainage of moisture from the base ledge and from the fin elements. More specifically, such means includes one or more openings provided in the outer perimeter of the ledge through which the moisture can drain overboard from the ledge. Preferably, the fin element assembly includes one or more vertical grooves or notches which extend transversely of the outer perimeter of the fin element assembly and which are aligned with a respective ledge opening to further promote overboard drainage of moisture from the fin elements.

A principal feature of the invention is to provide a flame arrestor for an internal combustion engine having improved resistance to the ingress of water into the engine air intake.

Other features, aspects, and advantages of the invention will become apparent upon reviewing the following detailed description, the drawing, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of a flame arrestor embodying various of the features of the invention.

FIG. 2 is a bottom plan view of the flame arrestor of FIG. 1.

FIG. 3 is an enlarged. fragmentary, sectional view taken along the plane designated 3-3 in FIG. 1.

FIG. 4 is an enlarged, fragmentary, elevational view of the flame arrestor of FIG. 1.

FIG. 5 is an enlarged, fragmentary, exploded view of the fin element assembly.

FIG. 6 is an enlarged, fragmentary, sectional view taken along the plane designated 6-6 in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Before explaining the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawing. The invention is capable of other embodiments and of being practiced and carried out in the various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purposes of description and should not be regarded as limiting.

Illustrated in the drawing is a flame arrestor 10 embodying various features of the invention. The flame arrestor I0 includes a base 12 having a generally cylindrical barrel section 14 which is adapted to be received by an air intake 16 (shown fragmentarily in FIG. 3) of a carburetor 18 (shown fragmentarily in FIG. 3) for an internal combustion engine (not shown), such as a marine propulsion stern drive. Extending radially outwardly from the barrel section 14 is an annular ledge 20. Extending upwardly from the outer perimeter of the ledge 20 is a upturned lip 21.

Supported on the ledge 20 is an annular fin element assembly 22 including a plurality of arcuately shaped, fin elements 24 which are stacked in vertically spaced, parallel relationship. Each of the fin elements 24 includes a plurality of integral, upstanding ribs 26 which are dimensioned so that, upon stacking the fin elements 24, narrow, radially extending air passages 28 are provided between vertically adjacent fin elements. The air passages 28 are wide enough to permit free passage of air into the carburetor intake 16 but narrow enough to prevent the passage of a flame front from the carburetor 18 when the engine backfires.

The fin elements 24 are arranged to prevent moisture from entering into the carburetor air intake 16 through the air passages 28. More specifically, each of the fin elements 24 includes an outermost edge 29 and an outer portion 31 which inclines radially and downwardly towards the outermost edge 29 so as to promote the overboard drainage of any moisture entering into the air passages 28. Preferably, the fin elements 24 have a generally inverted V-shaped cross section as shown in FIG. 3.

While the fin elements can be of various arrangements to form the annular fin element assembly 22, in the construction illustrated, the planar configuration of each of the fin elements 24 is generally in the form of a circular arc and the fin elements 24 are assembled to form a series of circumferentially spaced, generally cylindrical segments 30. Positioned between adjacent of the segments 30 is a T-shaped column 32 which has a radially extending leg 34 located in the spacing between the fin element segments 30 and a cross leg 36 generally abutting the inner edges of the fin elements 24 of adjacent segments 30.

Overlying the fin elements 24, the ledge 20, and the carburetor air intake 16 is a circular. generally horizontally extending cover 40. The base 12. the fin elements 24, and the cover 40 are connected together to form a unitary assembly by suitable connecting means, such as a plurality of rivets 42 which extend through axially aligned apertures 44., 46, and48 provided in the cover 40, the fin elements 24, and the base 20, respectively. Upon assembly the columns 32 are captured between the cover 40.and the ledge 20.

The flame arrestor is removably secured to the carburetor air intake 16 by suitable fastening means. Although various arrangements can be used, in the illustrated construction, such fastening means includes a cap bolt 50 which extends through a central aperture in the cover 40 and is threaded into a spindle 52 which in turn is threaded into a spider 54 (shown fragmentarily in FIG. 3) provided in the carburetor air intake [6.

In accordance with the invention, the cover 40 includes means for preventing the drainage of moisture from the cover 40 into the carburetor air intake 16. More specifically, the cover 40 has an outer portion 60 which extends radially outwardly beyond, i.e., overhands. the outermost edges of the stacked fin elements 24 so that moisture draining off the cover 49 does not impinge onto the fin elements 24. In order to further prevent draining moisture from impinging on the fin elcmcnts. there is provided on the cover 40 a flange 62 which depends from the outer perimeter of the cover 40. Still further, in order to prevent moisture accumulation on the cover. and particularly at the center therof, the cover includes (as seen in FIGS. 1 and 3) a central portion which tapers upwardly from the outer portion 60 to the center adjacent the cap bolt 50.

Also, in accordance with the invention, the base 12 includes means for preventing the drainage of moisture from the ledge into the carburetor intake 16. While various arrangements can be used, in the construction illustrated, the base 12 includes a continuous, annular raised portion 64 which is integral with the ledge 20 and which is located generally adjacent the inside edges of the bottommost fin elements 24 to act as a barrier or darn against moisture which may collect on the ledge 20.

Further in accordance with the invention, means is provided for affording the overboard drainage of moisture from the ledge 20. While various arrangements can be used, in the construction illustrated. such means comprises one or more openings 66 in the upturned lip 21 through which moisture can drain overboard from the ledge 20. In order to further promote overboard drainage of water from the fin element 24 on the ledge 20, the outer corners of the fin elements 24 are preferably cut off or bevelled, as seen in FIG. 1 so that, when assembled, the adjacent fin clement segments extending from the respective column 32 disposed therebetween, form a vertical, generally V-shaped groove or notch 68, as shown in FIG. 1. The notch 68 extends transversely of the outer perimeter of the fin element assembly 22 and are generally aligned with respective of the openings 66.

Various features of the invention are set forth in the following claims.

I claim:

I. A flame arrestor for an internal combustion engine including an air intake, said arrestor including an assembly of a plurality of vertically spaced fin elements forming an annular stacked array having a top, each of said fin elements having an outermost edge and an outer portion which inclines radially downwardly towards said outermost edge, said fin element at the bottom of said array including an inner edge, a base having a barrel section adapted to be received by the engine air intake, an annular ledge extending radially outwardly from said barrel section for receiving said fin clement assembly, and a continuous, annular raised portion which is integral with said ledge and is located generally adjacent to said inner edge so as to act as a barrier against water draining from said ledge into the engine air intake, and a generally horizontal cover overlying said top of said fin element assembly and terminating in an outer edge portion which extends radially beyond the outermost edges of said fin elements and said ledge.

2. A flame arrestor according to claim 1 wherein said fin elements have a generally inverted V-shaped cross section.

3. A flame arrestor for an internal combustion engine including an air intake, said arrestor including an assembly of a plurality of vertically spaced fin elements forming an annular stacked array having a top, each of said fin elements having an outermost edge and an outer portion which inclines radially downwardly towards said outermost edge, a base having a barrel section adapted to be received by the engine air intake, an annular ledge extending radially outwardly from said barrel section for receiving said fin element assembly and including an outer perimeter, said base also including an upturned lip extending from said outer perimeter of said ledge, said lip including means defining an opening for affording drainage of moisture from said ledge, and a generally horizontal cover overlying said top of said fin element assembly and terminating in an outer edge portion which extends radially beyond the outermost edges of said fin elements and said outer perimeter of said ledge.

4. A flame arrestor according to claim 3 wherein said fin elements have a generally inverted V-shaped cross section.

5. A flame arrestor according to claim 3 wherein said fin element assembly includes a generally vertical notch extending in general alignment with said lip opening.

6. A flame arrestor for an internal combustion engine including an air intake, said arrestor including an assembly of a plurality of vertically spaced fin elements forming an annular stacked array having a top, said fin elements each being of generally inverted V-shaped cross section and including an inner edge and an outer edge, a base having a barrel section adapted to be received by the engine air intake, and annular ledge extending radially outwardly from said barrel section for receiving. said fin element assembly and terminating in an upturned lip, said lip including means defining an opening for affording the drainage of moisture from said ledge, a continuous, annular raised portion on said base located generally adjacent to said inner edge of the bottommost of said fin elements to act as a barrier 5 6 against moisture draining from said ledge into the em 7. A flame arrestor according to claim 6 wherein said gine air intake, and a generally horizontal cover overlyfin element assembly includes a generally vertical ing said top of said fin element assembly and terminatnotch extending in general alignment with said lip ing in an outer edge portion extending radially beyond opening. said outer edges of said fin elements and said ledge. 5 

1. A FLAME ARRESTOR FOR AN INTERNAL COMBUSTION ENGINE INCLUDING AN AIR INTAKE, SAID ARRESTOR INCLUDING AN ASSEMBLY OF A PLURALITY OF VERTICALLY SPACED FIN ELEMENTS FORMING AN ANNULAR STACKED ARRAY HAVING A TOP, EACH OF SAID FIN ELEMENTS HAVING AN OUTERMOST EDGE AND AN OUTER PORTION WHICH INCLINES RADIALLY DOWNWARDLY TOWARDS SAID OUTERMOST EDGE, SAID FIN ELEMENT AT THE BOTTOM OF SAID ARRAY INCLUDING AN INNER EDGE, A BASE HAVING A BARREL SECTION ADAPTED TO BE RECEIVEED BY THE ENGINE AIR INTAKE, AN ANNULAR LEDGE EXTENDING RADIALLY OUTWARDLY FROM SAID BARREL SECTION FOR RECEIVING SAID FIN ELEMENT ASSEMBLY, AND A CONTINUOUS, ANNULAR RAISED PORTION WHICH IS INTEGRAL WITH SAID
 2. A flame arrestor according to claim 1 wherein said fin elements have a generally inverted V-shaped cross section.
 3. A flame arrestor for an internal combustion engine including an air intake, said arrestor including an assembly of a plurality of vertically spaced fin elements forming an annular stacked array having a top, each of said fin elements having an outermost edge and an outer portion which inclines radially downwardly towards said outermost edge, a base having a barrel section adapted to be received by the engine air intake, an annular ledge extending radially outwardly from said barrel section for receiving said fin element assembly and including an outer perimeter, said base also including an upturned lip extending from said outer perimeter of said ledge, said lip including means defining an opening for affording drainage of moisture from said ledge, and a generally horizontal cover overlying said top of said fin element assembly and terminating in an outer edge portion which extends radially beyond the outermost edges of said fin elements and said outer perimeter of said ledge.
 4. A flame arrestor according to claim 3 wherein said fin elements have a generally inverted V-shaped cross section.
 5. A flame arrestor according to claim 3 wherein said fin element assembly includes a generally vertical notch extending in general alignment with said lip opening.
 6. A flame arrestor for an internal combustion engine including an air intake, said arrestor including an assembly of a plurality of vertically spaced fin elements forming an annular stacked array having a top, said fin elements each being of generally inverted V-shaped cross section and including an inner edge and an outer edge, a base having a barrel section adapted to be received by the engine air intake, and annular ledge extending radially outwardly from said barrel section for receiving said fin element assembly and terminating in an upturned lip, said lip including means defining an opening for affording the drainage of moisture from said ledge, a continuous, annular raised portion on said base located generally adjacent to said inner edge of the bottommost of said fin elements to act as a barrier against moisture draining from said ledge into the engine air intake, and a generally horizontal cover overlying said top of said fin element assembly and terminating in an outer edge portion extending radially beyond said outer edges of said fin elements and said ledge.
 7. A flame arrestor according to claim 6 wherein said fin element assembly includes a generally vertical notch extending in general alignment with said lip opening. 